[QUOTE=bobdod04;2992384
- I went back to reconnect the battery. when I put the terminal back on, I had sparks and lots of heat at the cable, slightly melting the post on the battery!
- now there is no power at all. no dash lights, no nothing. I did a visual check on all the fuses under the hood and inside the panel by the driver side door. didn't see any blown fuses.

What the heck happened and how do I fix it?[/QUOTE]

There is no fuse in the main cable between the battery and the starter. The current is normally limited by the internal impedance of the starter, as well as by the cable resistance and the internal battery resistance. As others have stated, your work on the starter terminal likely resulted in a dead short at the starter. This allowed the battery to attempt to deliver max current (600 amps or more), and may well have damaged the battery internally, since you say the post was melting.

There's no reason to expect any fuses to have blown, or for the ECU to be bad. Neither the ECU nor any fuses were in the path of all that current. My guess is your battery is toast. A simple test is to pull out your multimeter and check the voltage across the battery terminals. Should be 12V or more.

And, by the way, how did you originally conclude the battery and alternator were OK and thus the problem must be the starter? 99% of intermittent starting problems are either a poor connection at the battery or starter, or an intermittent cell internal to the battery. Both of those conditions can be temperature sensitive. (And remember, there are four connections involved in the high current starter circuit - both battery terminals, the large starter cable to starter, and battery ground cable to frame. All of those need to be squeaky clean and tight.)